This invention relates generally to fasteners, and more particularly to slide fasteners, commonly known as "zippers", and a method of making the same, which may be used to fasten more than two sets of teeth or links together. The invention may also be used to provide a collapsible, rigid support for loads which may applied axially and laterally to the fastened links. The invention may further be used to provide a means for joining two sets of elongated links together.
Slide fasteners or zippers, which can be used to attach an edge of a piece of sheet material to an edge of another piece of sheet material, are well known. In such, each of the edges to be fastened together has a row of teeth or links. A slider tool is drawn over the teeth to enable them to lock together.
In addition, slide fasteners for fastening three pieces of sheet material are known, as shown in U.S. Pat. Nos. 2,483,057 to Levering and 4,112,552 to Lee. In these fasteners, one piece of sheet material has mounted along one edge a set of double-sided teeth, with each side of the double-sided teeth fastening to single-sided teeth mounted on one edge of each of the other two pieces of sheet material. A single slider is disclosed in these patents for enabling the fastening of the single-sided teeth with the central dual-sided teeth.
In addition, it has been known to make collapsible structural members, such as disclosed in U.S. Pat. No. 3,213,573 to Bohr et al. In the Bohr et. al. patent, a complicated apparatus including peeler drums and peeler rollers is disclosed for interlocking and unlocking solid strips of material having interlockable edges.